(1) Field of the Invention
The present invention relates to a method for cutting a protective tape of a semiconductor wafer and a protective tape cutting device for relatively moving a cutter blade with respect to the semiconductor wafer along an outer periphery of the semiconductor wafer to cut out the protective tape joined to a surface of the semiconductor wafer.
(2) Description of the Related Art
In the above protective tape cutting method, the cutter blade is relatively moved along the outer periphery of the semiconductor wafer having a positioning notch on the outer periphery. In this case, the tape on a V-shaped notch portion is cut in the following manner. When the cutter blade passes through a first part of the notch, a blade edge thereof is rotated so as to be directed towards a center of the wafer. When the cutter blade passes through a latter part of the notch, the blade edge is rotated so as to be directed towards the outer periphery of the wafer (see Japanese Laid-Open Patent Publication No. 2006-15453).
According to the protective tape cutting method described above, the protective tape is not greatly exposed to remain in an interior of the notch, and thus it is effective in suppressing attachment of dust in comparison with a case where the remaining protective tape exists in the notch. However, the cutter blade reaches a deep part of the notch while cutting the tape along an oblique side in the first part, and the tape is set in the latter part such that a cut-in angle of the blade edge of the cutter blade is set substantially perpendicular to an inner edge of the notch. Therefore, there arise problems such as the blade edge cutting into the inner edge of the notch to damage the semiconductor wafer or the blade edge being worn at an earlier time. In particular, the recent thinned semiconductor wafer with less rigidity tends to be more easily damaged at the portion formed with the notch due to the cutter blade being in contact with or sticking in the wafer.